How to get a new BFF in MCPE.
Step 1: Getting the Supply
Make your world creative and get a "Anvil" and a "Spawn Egg" of any kind.
Step 2: Working in Anvil
After you have set down your "Anvil" press on it as you would if you were about to work in a "Crafting Table". You will see 4 boxes on your screen and your inventory. It is already highlighting the first box so, press on the egg in your inventory. It will be set in the first box. Now there will be a box on top of the three others. Press on it and put in a name or other title. After you have pressed done you will see an egg in the third box. The cost for it is 1 XP. Press on the egg in the third box 2x to put in your inventory.
Step 3: Spawning the Creature
Now that you have the egg... We need to spawn it! Press the ❌ to get out of the Anvil. Go to your inventory and press on the named egg. Now set it on the ground.
Step 4: Enjoy!
Tame your pet with the food they like. Now they love you! Enjoy your new companion!